Sound, a good set of equal length headers with proper cats and X pipe will give a sound that modifying the other parts of the exhaust only cannot match.

 

Tervuren!
That's true! "BUT" Headers are for HP not so much "sound".....I've got "sound" for less than $1,500.00...with XJR Manifolds, Magnaflow 200 Cell Cats and a Magnaflow X Pipe Double Muffler that go into the Rear Quicksilver Mufflers....These Headers are good looking but can't make enough HP to justify 5 Grand...and I can't see paying that for sound as it just couldn't be any better!!
Tervuren, I think that the Magnaflow X Pipe Double Muffler improves the XKR's sound more than anything I've tried over the past 18 or 19 years....

Billy Clyde

 

Yes finally a proper made header that would deliver a legitimate gain in hp but grossly overpriced.

 

Where is the header project for the 5.0 stand?

 

Stuart from velocityap was developing a set for the 5.0 due to lack of interest he has literally benched it

As far as I know there is one prototype set

 

Is this project going to be laid to rest from lack of interest?

 

No point for the s/c guys although for the n/a units the headers will make power

I might contact Stuart and see if he is willing to let go of his prototype version for the V8

 

I have everything sitting in the shop ready to go together. I have just been torn whether to move forward or not. I have a variety of projects that all take investments if I could justify this one I would move forward. With the time and effort to design these it only makes sense to make the fixture while the car is taken apart. So oh a low end I'm assuming my costs to be pretty high to design/build/test. Just so you understand the costs price out a properly designed collected that has a proper merge and divergent angle. I have 2k nearly in just the collectors and fittings.
I have quite the investment in carbon molds already and the jag crowd is a tough on to market to as most do not want to modify. I do this more for my personal love of these cars.
There's a lot of risk with building this set for the 4.2 as I know it will definitely fit 07-09 XK/XKR but I don't know earlier models. I may be able to mod for the 5.0 but again that may be an additional fixture and design time. So this just = more money.
Im tossing up the idea of just moving forward, I've been working on files for a whipple coversion so I'm going to consider doing one of the other first.
I'll keep you guys posted. Sorry for silence for a bit. I was out of the country for 3 months and my VPN wasn't working too well.
Check anoher thread I'll be posting with carbon fiber interior completed.

 

The carbon fiber is a bit of a hard sell, as a significant percentage chose Jaguar in order to have wood trim over carbon fiber. Its also out of sight(in the engine bay parts).

I'm at a point I want to go with a full exhaust build, but I don't want to do be doing it twice.

One thing I'm not sure was addressed, is it going to be an engine out install as was brought up earlier?

 

Me, I'd be more interested in a Whipple conversion, IF it isn't exorbitantly priced.

 

Fully agree. I'm an auto nut myself and work so much on high end designs that I always wanted to see a Jag that is done similarly to a One-77. So that's why I started this process. It may take me a few years but that's the goal.
I am going to finish this setup and follow through with the headers. It's just a matter of which project comes first. I may consider selling a few whipple setups once complete.
I will put my thoughts together and put together a timeline to complete this.
It certainly has been driving me crazy looking at these beautiful collectors on my desk and not on the car.

 

If you have time I would mock up a set of prototypes and see how they behave. At least then you'll know if it's a dead end project. I've backed away from a couple great ideas were the juice just wasn't worth the squeeze when it was all said and done. Labor, material expense, install difficulty or maintenance problems just weren't worth the limited gains.

I think Avos' twin screw project is a much better ROI vs a set of headers for gain over a similar RPM range.

 

Fricken,

The people in Italy have beat you! Now this is a nice set of Headers! Don't you think? They will fit a 2005-2006 4.2 just fine......Only cost about $5,000 to Houston!

Billy Clyde



Italian Headers for the 2005-2006 XKR

 

Supersprint

 

 

Ditto. I'd be curious what a set of extrude honed castings would cost and what increase they would allow.

 

Fricken,

So! You are saying that I would be wasting my money and that yours would give me more Power-Output, but you also say that you don't think your design would fit the 2003 to 2006 XKR and you are basically designing yours for the 2007 up. Hmmmm! I guess I'll have to continue using my current set-up, which is using the "Ported" XJR Exhaust Manifolds that 45 out the back into 21/2" Pipes. I guess that Pipe would be my "Merge Collector"...They run down about 10" to 21/2" 200 Cell Cats.... The sound is great (Mild) but I don't know if they create any vacuum in the "Merge Collectors"! Anyway, they are hooked-up to a Magnaflow 21/2" double Muffler and on out through the remnants of my old Quicksilver Exhaust system....I was told that this Muffler is basically an X-Pipe (inside). I don't know for sure but it sounds like a good idea...

Also, if I were to make-up a Merge-Collector that basically looks like the one you have designed...Understanding it is not really merging, just accepting the Manifold flow into your design.....would that create any advantage or should I just forget it? I mean the necking down to about 2" and bringing it back out to 21/2" as your design?

Your thoughts on this, Please! I would appreciate your comments...

Billy Clyde in Houston

 

This has been on the back burner of things I'd like to do when I have the time- get a set of manifolds off Ebay for about $130, then have them flow benched before and after being extrude honed to see where we're at with them. I figure, everyone that says they want headers or says the cars need them have yet to show that the stock manifolds are garbage. I could justify $5k for headers if they could show me how bad the stock logs are and how much better (both on the flow bench and on the dyno) their headers are.

 

I was thinking of doing the same thing for my S-Type R. I am assuming if they fit the S type R they will fit anything else since the STR has the tightest engine bay. I would do a dyno of before and after maybe. Depends if the shop I am in contact with would be up to it

 

insomniac--driver & Mandrake,

The Exhaust Manifolds for the 2005 XJR are in fact Mini-Headers....They collect the exhaust gasses from 2 cylinders per runner and dump each runner into the 2" Exhaust Pipe that runs down to the Cat Convertor.....They are similar to the XKR Manifolds except they have a Ball Connector on the end instead of a Gasket Connector that connects to the top of the big Trash Can looking Cat Converter. This connection on the XKR completes a full 90 degree turn that the gases have to go thru immediately upon exiting the Engine.......The XJR exits at a 45 degree turn and continues on down to the Cat and then makes another 45 degree turn into the Muffler system... This Manifold, after being Extrusion Honed, Match Ported and Ceramic Coated inside and out, will actually work about the same as those $5,000.00 Headers we saw from Italy! My Heads have been ported and ceramic coated, so all the Manifold inlets will be match Ported to them! The Gaskets and Heat Shields are all stock Jaguar and everything fits just like they came from the Factory! The set I got from eBay cost me about $120.00....I will send Photos of them as soon as they come back from the Honing Company in California before installing them in place of my current ones!....This Manifold will fit any of the 4.2 Jaguar Engines but you need to be concerned about the EGR connection as you may have to make up one for the XKR.. Be aware of this as it is different on the XJR!

How much will it cost? I will let you know that also......The Company that does the Honing is in Paramount, CA.........Think about this for a minute, the XKR's Engine only has 256 Cubic Inches of volume....By comparison, the first Chevy V8 back in 1955 had 265CI. The AJ-V8 is a little bitty Engine which creates volume though RPM's and Supercharged Pressure. Therefore, any relief, such as Porting the Heads, relieving pressure through the exhaust system will help this Engine build Horsepower and Torque. I feel it is important to improve the exhaust system on the XKR....

Billy Clyde

The XJR Exhaust Manifolds are almost Cast Headers